16 research outputs found

    Press Code: A Shoulder Surfing Resistant Authentication Scheme for Smart Devices

    Get PDF
    A memorization-based locking system is widely used in today’s smart devices, where a user has to repeat a text/number/pattern/others from the remembrance that has been registered before. He/she would be allowed to access the device if the newly given password is matched with the registered one. However, among this class of passwords, graphical password schemes are more compatible for smart devices due to their heavily graphic-oriented nature. However, existing graphical password schemes experience various attacks and threats. Among them shoulder surfing is the most prominent one, where an attacker can observe the password through picking on the screen. In this project, we propose a shoulder surfing resistant password scheme using press code, which is a new kind of code; and hence, a novel authentication scheme. In the proposed technique, a user can authenticate thyself by repeating the registered press code. We implement our proposed technique on the Android platform, and we have a prototype to demonstrate at present

    Impact of Myocardial Viability Assessed by Delayed Enhancement Cardiovascular Magnetic Resonance on Clinical Outcomes in Real World Practice

    Get PDF
    Background: Delayed enhancement cardiovascular magnetic resonance imaging (DeCMRI) has become the preferred method for viability assessment. It is well established that viable dysfunctional myocardium has the potential for functional recovery after revascularization. Objective: Our objective is to evaluate whether viability assessment by DeCMRI affects clinical outcome in daily clinical practice. Methodology:We retrospectively studied 132 consecutive patients (114 male, mean age 59 ± 10 years) with ischaemic cardiomyopathy (Mean LVEF: 29.1 ± 14%) who underwent CMRI viability testing from 1st Jan-31st Dec 2015 in our centre. Patientswere divided into 3 groups: Group A: Viable myocardium- optimal medical therapy only (38.6%); B: Viable myocardium- revascularization done (29.5%); and C: Nonviable myocardium (29.5%). Results: Mean age for groups A, B and C were 61.2, 58.3, 56.2 years respectively, p=0.048. The proportion of triple vessel disease in each of the groups were 56.1%, 54.5% and 38.5% (p=0.44); whereas left main involvement was 31.7%, 21.2% and 19.2% respectively (p=0.43). Majority of group C patients did not undergo revascularisation (90%). Group B had statistically significant EF improvement (5.5%, SD 11.9) compared to Group A (-0.6%, SD 6.7) and Group C (-1.2%, SD 9.8), p value 0.014. Mortality at 1 year was significantly higher in Group A compared to Group Band C (31.4%, 7.7% and 12.8% respectively, p=0.009). MACE rates were also increased in Group A compared to the other two groups (41.2%, 20.5% and 27.0%, p=0.09). Odds Ratio for MACE was 3.01 (95% Cl 1.22 - 7.45) for Group A vs B and 2.8 (95% Cl 1.1 - 6.9) for Group A vs C. Conclusion: Patients with viable myocardium who did not undergo revascularization (group A) had the worst prognosis, even when compared to those with non-viable myocardium; with significantly higher 1-year mortality. Although not statistically significant, there was also a trend towards higher MACE in these patients. These findings emphasize that patients with poor LV function but viable myocardium need to undergo revascularisation and that optimal medical therapy alone is not sufficient

    Effect of solder bump size on interfacial reactions during soldering between Pb-free solder and Cu and Ni/Pd/Au surface finishes

    Get PDF
    Flip chip technology provides the ultimate in high I/ O-density and count with superior electrical performance for interconnecting electronic components. Therefore, the study of the intermetallic compounds was conducted to investigate the effect of solder bumps sizes on several surface finishes which are copper and Electroless Nickel/ Electroless Palladium/ Immersion Gold (ENEPIG) which is widely used in electronics packaging as surface finish for flip-chip application nowadays. In this research, field emission scanning electron microscopy (FESEM) analysis was conducted to analyze the morphology and composition of intermetallic compounds (IMCs) formed at the interface between the solder and UBM. The IMCs between the SAC lead-free solder with Cu surface finish after reflow were mainly (Cu, Ni)6Sn5 and Cu6Sn5. While the main IMCs formed between lead-free solder on ENEPIG surface finish are (Ni, Cu)3Sn4 and Ni3Sn4. The results from FESEM with energy dispersive x-ray (EDX) have revealed that isothermal aging at 150 degree Celsius has caused the thickening and coarsening of IMCs as well as changing them into more spherical shape. The thickness of the intermetallic compounds in both finishes investigated was found to be higher in solders with smaller bump size. From the experimental results, it also appears that the growth rate of IMCs is higher when soldering on copper compared to ENEPIG finish. Besides that, the results also showed that the thickness of intermetallic compounds was found to be proportional to isothermal aging duration

    Press Touch Code: A Finger Press based Screen Size Independent Authentication Scheme for Smart Devices

    Get PDF
    Due to recent advancements and appealing applications, the purchase rate of smart devices is increasing at a higher rate. Parallely, the security related threats and attacks are also increasing at a greater ratio on these devices. As a result, a considerable number of attacks have been noted in the recent past. To resist these attacks, many password-based authentication schemes are proposed. However, most of these schemes are not screen size independent; whereas, smart devices come in different sizes. Specifically, they are not suitable for miniature smart devices due to the small screen size and/or lack of full sized keyboards. In this paper, we propose a new screen size independent password-based authentication scheme, which also offers an affordable defense against shoulder surfing, brute force, and smudge attacks. In the proposed scheme, the Press Touch (PT)—a.k.a., Force Touch in Apple’s MacBook, Apple Watch, ZTE’s Axon 7 phone; 3D Touch in iPhone 6 and 7; and so on—is transformed into a new type of code, named Press Touch Code (PTC). We design and implement three variants of it, namely mono-PTC, multi-PTC, and multi-PTC with Grid, on the Android Operating System. An in-lab experiment and a comprehensive survey have been conducted on 105 participants to demonstrate the effectiveness of the proposed scheme

    Electroless and immersion plating process towards structures and IMC formation

    No full text
    The selection of surface finish on printed circuit board is very important in soldering process because it can prevent the copper from oxidation and provide solderable surface. It is also will influence the cost, manufacturing, shelf life, surface quality, final product reliability and environment.Electroless and immersion plating process has now become an important and popular surface finish in electronic industry due to simple and low cost process. The application of electroless plating are widely used in electronic industry, however it also was used in various industries such as aerospace, automotive, oil and gas, chemical processing where the need on the complex shape, homogeneous and uniform layer are required. Besides, every surface finish has their strength and weakness. Immersion silver is one of the surface finishes frequently used on the printed circuit board due to their characteristics such as good solderability and wettability, easy assembly and low cost. Both of these two processes were acts as barrier layer between copper substrate and solder balls. This review was discussed about electroless nickel and immersion silver plated on copper substrate, coating process and parameters involved. The topic also covered include the morphology and thickness of the intermetallics formed during soldering as well as the isothermal aging process

    Press touch code: A finger press based screen size independent authentication scheme for smart devices - Fig 4

    No full text
    <p>(a) Flowchart of the registration phase of the multi-PTC variant and (b) Flowchart of the authentication phase of the multi-PTC variant.</p

    The password space, P for three variants of the proposed scheme when <i>μ</i> = 10 and <i>N</i> = 4.

    No full text
    <p>The password space, P for three variants of the proposed scheme when <i>μ</i> = 10 and <i>N</i> = 4.</p
    corecore